Free Vibration Analysis of Asymmetric Buildings
A simple procedure for free vibration analysis of asymmetric buildings is presented. This method assumes that each floor is a rigid diaphragm with three degrees of freedom (two lateral...
Wave Propagation in a Nonlocal Strain-Softening Continuum
The problem of wave propagation in a nonlocal strain softening solid is first discussed analytically. It is demonstrated that 'loading' waves can still propagate in the strain softening...
Routes to Chaos of a Vertically Rotating Pendulum
Each blade of a mechanical shredder may be modeled by a pendulum whose pivot rotates in a vertical circle. The transition to chaos of small periodic motion about radial lines us the driving...
Roll-Waves on a Non-Newtonian Mud Layer
This article extends the theory of roll-waves due to Dressler (1949) to a thin layer of mud modeled as a power law fluid. Roll-waves are periodic bores moving at a constant velocity down...
Inflation Instability of Cylindrical Membranes
A new procedure which investigates inflation instability of cylindrical nonlinear membranes is developed. The general characteristics of inflation instability are described. An efficient...
Stochastic Finite and Boundary Elements
The random coefficients in partial differential equations, which govern the responses of stochastic thermo-mechanical systems, (Dasgupta, 1991), pose a computational challenge. The large...
Investigation of Parametrically-Induced Excitation in Concrete Columns
A mathematical model is developed which accounts for the non-linear material characteristic of concrete members. The axial and transverse motions of concrete columns, are found to be second-order...
Lunar Habitats?Places for People
As part of President George Bush's Space Exploration Initiative, lunar bases or habitats are envisioned for long-term habitation by humans. This paper presents factors that should be considered...
The Design of a Permanent Lunar Research Station
The advancement of the United States efforts in space exploration and research requires the establishment of a permanent manned lunar research station. This paper explores the possible...
Tripod Crane Concept for Lunar Surface Construction
A construction scheme using three integrated cranes is proposed. Mikulas proposed a lunar crane concept which introduces a set of three cables in order to stabilize the payload. This paper...
Construction Challenges on Planetary Surfaces
In July 1989 those who advocate a vigorous U.S. space program received a significant boost from the President's declaration that we should return to the Moon, this time to stay, and then...
Mechanical Properties of Lunar Soil and Simulants
Investigation of the physical and mechanical properties of lunar soil carried out by the USSR and the USA; both in situ and on returned samples, has resulted in considerable information...
Hydrogen Reduction of Lunar Soil and Simulants
Carbotek, Inc., and the Energy and Environmental Research Center (EERC) are cooperating on further development of the Carbotek process to produce oxygen from lunar ilmenite by hydrogen...
Steady State Composition with Low Fe?+ Concentrations for Efficient O2 Production by Magma Electrolysis of Lunar Soils
Parameters are estimated for a hypothetical, well stirred, continuous-feed electrolytic cell that converts 20% of a lunar soil feedstock to O2 gas,...
Phased Assembly of a European Space Station
This paper discusses a phased assembly approach for a proposed European Space Station utilising a series of constructional payloads that are delivered to orbit in an established sequence...
Tethers and Their Role in the Space Exploration Initiative
This paper addresses some potential applications for tethers in space, and describes a mission designed to deploy a satellite from a Delta II launch vehicle, by NASA's Small Expendable...
On-Orbit Assembly of Large Space Structures: A Mars Aerobrake Mock-up Study
As design requirements for space structures become larger in dimension, the issues of shipping and assembling these structures in space become more critical. One example of such a structure...
Mechanical Properties of Compacted Lunar Simulant Using New Vacuum Triaxial Equipment
Mechanical stress-strain-strength properties of Arizona Lunar Simulant (ALS) are investigated by using a newly developed vacuum triaxial device that allows compaction under different initial...
Steam Injection System for Lunar Concrete
Since January 1989, the Department of Civil Engineering at the United States Air Force Academy has been conducting research on the use of concrete for constructing permanent facilities...
Robotics in SEI Terrestrial Launch Site Operations
This paper addresses work performed at Rockwell International's Space Systems Division, Downey, California. Future Space Exploration Initiative (SEI) missions will require terrestrial...
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